• Communications for Statistical Applications and Methods
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• v.17 no.6
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• pp.899-907
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• 2010

Several non-response imputation methods are suggested, however, mainly cross-sectional imputations are studied and applied to this analysis. A simple and common imputation method for panel data is the cross-wave regression imputation or carry-over imputation as a special case of cross-wave regression imputation. This study suggests a multiple imputation method combined time series analysis and cross-sectional multiple imputation method. We compare this method and the cross-wave regression imputation method using MSE, MAE, and Bias. The 2008 monthly labor survey data is used for this study.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.817-825
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• 2022

A recent benchmarking effort, under the auspices of the Organization for Economic Cooperation and Development (OECD) Nuclear Energy Agency (NEA), has been made to evaluate the current state of modeling and simulation tools available to model fluoride salt-cooled high temperature reactors (FHRs). The FHR benchmarking effort considered in this work consists of several cases evaluating the neutronic parameters of a 2D prismatic FHR fuel assembly model using the participants' choice of simulation tools. Benchmark participants blindly submitted results for comparison with overall good agreement, except for some which significantly differed on cases utilizing a molybdenum-bearing control rod. Participants utilizing more recently updated explicit isotopic cross sections had consistent results, whereas those using elemental molybdenum cross sections observed reactivity differences on the order of thousands of pcm relative to their peers. Through a series of supporting tests, the authors attribute the differences as being nuclear data driven from using older legacy elemental molybdenum cross sections. Quantitative analysis is conducted on the control rod to identify spectral, reaction rate, and cross section phenomena responsible for the observed differences. Results confirm the observed differences are attributable to the use of elemental cross sections which overestimate the reaction rates in strong resonance channels.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.2
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• pp.145-153
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• 2020

The purpose of this study is to investigate the effects of composition of underground structural wall and H-pile in soil cement. The results of previous experimental studies are re-analyzed and the nonlinear cross-sectional analyses of composite basement walls are performed to verify their nonlinear flexural behavior. Based on the study, it is explained how the gap deformation between H-Pile and RC wall should be considered in the design of flexure of composite underground walls. The nonlinear cross-sectional analysis shows that the load-displacement curves of composite basement wall specimens exhibiting flexural behavior exist between the results of the analysis of the complete and non-composite cases. When predicting the behavior of the composite basement wall by nonlinear cross-sectional analysis, the flexural behavior of the composite basement wall could be suitably predicted by considering the reduction of the composite ratio due to tensile stress acting on shear connectors.

• Journal of the Optical Society of Korea
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• v.2 no.2
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• pp.58-63
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• 1998

Cross-talk effects in high-density volume holographic interconnections are investigated using perturbative iteration method of the integral form of Maxwell's wave equation. In this method, the paraxial approximation and negligence of backward scattering introduced in conventional coupled mode theory is not assumed. Interaction geometries consisting of non-coplanar light waves and multiple index gratings are studied. Arbitrary light polarization is considered. Systematic analysis of cross-talk effects due to multiple index gratings is performed in increasing level of diffraction orders corresponding to successive iterations. Some numerical examples are given for first and third order diffraction.

• International Journal of Contents
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• v.8 no.4
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• pp.50-55
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• 2012

This study compared cross-national Twitter use between Korea and Japan. The main exploratory variables were a) cultural traits and b) disclosure of geographic information. Twitter use was measured by the degree of reciprocity and the numbers of Tweets, followings, and followers. Data were collected using API-based software and analyzed with independent samples t-tests. Content analysis was conducted to validate the findings. The results indicate that Korean and Japanese users employ their own communication strategies reflecting their cultural orientation.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1224-1227
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• 1998

This paper presents an effect of cross magnetization to the generator characteristics in synchronous machine infinite bus system. Eigenvalues, synchronous torque and damping torque are investigated as the operating condition of the system is changed variously. The simulation results show that cross magnetization has an important effect to the generator characteristics in steady state stability analysis.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.393-398
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• 2006

This study is undertaken to evaluate the characteristics of cross contamination around exterior air-vents. A CFD analysis has been performed to calculate the cross contamination index for five exterior air-vents sizes according to the outdoor air velocity and separation distance of it. From the result of the numerical method, As the outdoor air velocity is increased, the cross contamination index is increased. on the contrary, as the separation distance of exterior air-vents is increased, the cross contamination index is decreased, additionally the cross contamination is affected by the aspect ratio of the size of exterior Air-vents.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.3
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• pp.170-175
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• 2018

While the term online shopping refers to all online transactions, cross-border online shopping means shopping activities purchasing products or services over the internet for the customers abroad. As Internet use for the international shopping activity increasing, cross border online shopping has grown substantially for last decade. This study is about the problem regarding the cross border online shopping for two different countries and the variables that influence their shopping behavior. The cross border online shopping has been increased by the growth of Internet access. However, the growth of the Internet use does not guarantee a successful development of cross border e-commerce for every country. To find out the perception for cross-border online shopping for two different cultures, shoppers from two countries with different cultural background were chosen, and the perception for cross-border online shopping from each culture is contrasted. For statistical Analysis, ANOVA is used to find the relationship between a single non-metric independent variable, and multiple metric dependent variables. Hofstede's cultural dimensions model is adopted for this study as a tool to find out the patterns of cross border online shopping. This study showed what the variables would affect the perception in cross border online shopping. The results of this study indicated that cross border online shoppers with different culture were notably different on two variables identified-timeliness and ease of use.

• Fire Science and Engineering
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• v.16 no.1
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• pp.24-29
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• 2002

The purpose of this study is developing the computer program for hydraulic design sprinkler systems have performed the means for the general use of network analysis method. The computer program is based on the theoretical concepts of the related Hazen-Williams equations, a modified Bernoulli equations, and the Hardy Cross method of pipe network analysis. Looped piping calculations are solved by using either the Hardy Cross method or the other iteration methods. While the other methods are solved using simultaneous equations, the Hardy Cross method is concerned with one loop at a time using reiterative process. Due to its simplicity the Hardy Cross method will be the primary method described in this thesis. The purpose of this study is to develope hydraulic calculation program by using algorithm for network analysis method. The development of computer program for the hydraulic design of sprinkler systems will perform the means in the performance-based sprinkler system design.

• Structural Engineering and Mechanics
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• v.52 no.1
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• pp.173-203
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• 2014

The cross-section warping due to the passage of high-speed trains can be a relevant issue to consider in the dynamic analysis of bridges due to (i) the usual layout of railway systems, resulting in eccentric moving loads; and (ii) the use of cross-sections prone to warping deformations. A thin-walled beam formulation for the dynamic analysis of bridges including the cross section warping is presented in this paper. Towards a numerical implementation of the beam formulation, a finite element with seven degrees of freedom is proposed. In order to easily consider the compatibility between elements, and since the coupling between flexural and torsional effects occurs in non-symmetric cross-sections due to dynamic effects, a single axis is considered for the element. The coupled flexural-torsional free vibration of thin-walled beams is analysed through the presented beam model, comparing the results with analytical solutions presented in the literature. The dynamic analysis due to an eccentric moving load, which results in a coupled flexural-torsional vibration, is considered in the literature by analytical solutions, being therefore of a limited applicability in practice engineering. In this paper, the dynamic response due to an eccentric moving load is obtained from the proposed finite element beam model that includes warping by a modal analysis.